Test Results for the Following:
Ammonia Level? 0
Nitrite Level? 0
Nitrate level? 20-30ish
Ph Level, (If possible,KH and GH and chloramines)? 6.8
Ph Level out of the Tap? slightly lower, I always have to raise it.
Tank size (How many Gals) and How long has it been running? 50, running for months now
What is the name and size of the filter/s? Emperor 280
How often do you change the water and how much? 25 to 30 percent weekly
How many fish in the tank and their size? small, ranchu and telescope, one dojo loach, and some small snails. And my sick Pleco!
What kind of water additives or conditioners? dechlorinator
Any medications added to the tank? nope
Add any new fish to the tank? not in over 2 weeks
What do you feed your fish? pellets?

Any unusual findings on the fish such as "grains of salt",
bloody streaks, frayed fins or fungus?
Any unusual behavior like staying
at the bottom, not eating, ect..?

My pleco has an overall loss of colour. He used to be almost black, now he's a milky brown. On his underbelly, there's a red undertone with streaks. On his fins, there's this chunky yellow stuff, with red dots close to his body. He was really easy to catch and I have him isolated now in a 15 gallon hospital tank with a filter and a bubbler. His gills are a bit red, too.

Please help. I'm at a loss...

Hi sorry to hear about your pleco.
The first thing I've noticed is that your filter is really small for that size of tank.You'd be much better off with a total gph(gallons per hour) with 10 x's filtration which is around 500 gph.Better yet,and Emperor 400 would be a great add on to what you allready have.
How often are you doing gravel vac's?
What are you using to test PH and Nitrates? What about ammonia & Nitrites?
What is your exact ph when out of the tap?
I'm really at a loss about this " chunky yellow stuff,".I don't picture what you mean.Is it possible to show a pic?
Your ph is on the low side for Goldies,but most Plec's can handle the more acidic ph's.Do you know what typr of Plec you have?
With all the redness on fins and body,and the red dots ,it sounds like it could be bacterial.With out knowing your exact water params,that is a guess on my part.Sometimes redness in fish will happen when poor water quality is a factor. I need to know a little bit more about this.Post soon.

Something's going on.....

Computer probs

I use these little test strips. One has pH, nitrAte, nitrIte all in one, and I use a seprate one for ammonia. I've also got a SeaChem ammonia alarm on the tank wall. I gravel vac every other waterchange.
My pleco is certainly NOT a common. Rubber something... I can't remember exactly rubberlip, rubberface, rubbernose...?

Exact pH out of the tap is 6.4 (I know, way low. But that's what my test kit said)

So a filter upgrade is in order? I believe you over the guy at the LFS who sold it to me saying it would be fine for my 50gal...

I'm at a bit of a loss myself, as all my other fish are in complete health. It seems to be just the pleco involved.

None of my photos so far has turned out. It looks like dark, rotten butter, and it's in clumps on the edge of some of the fins.

Thanks Devs... you're like the site doctor

Thanks for the vote of confidence Missy,I do try.
A little secret about Test strips--even though I use them for emergencies,they are(param readings) usually worse when I do the drop test kit.
You can get Aquarium Pharmaceutical's test kit on line at Big Al's for 12.99--much much more accurate for sure.
The guy at the LFS could have been right if maybe talking about a Tropical tank-to tell you the truth,I don't even know the recommendation for those anymore.Even in my Trop tanks,I use alot of filter power.As long as it's not slamming the fish around of course.
It's really hard on what to say here without accurate readings.I think if it were me though,I'd probably do a big water change just to get the ball rolling.
Your tap ph is really low-even worse than mine.Do you happen to be using ph up by chance,or are you using baking soda,or even crushed coral?
With the ph that low,I'm really wondering if that plec's not peeling from a ph crash. Some fish are just more vulnerable than other's.whatever,with the red spots showing up now,it may have gone to a secondary bacterial infection.
See how he's doing in the Q-tank for a while and if he's acting a bit better.Do you happen to have any meds in the house?

I went back to the LFS to see what they said, and the specialist there said that the yellow stuff was completely over her head too. I've got a product called LifeGuard, by Jungle labs. It says it's a broad spectrum treatment for a lot of diseases. I figure I'll give it a go.

I've done a big waterchange in the main tank, but he's been in the QT since I noticed him acting screwy.

As for other meds, I have melafix, fungus clear (Jungle) Maracyn, Maracyn Two, and some anti-ick from PetCetera. (Yeah, after Squishy the first, I keep a lot of meds on hand.)

I'm using pH up, also by Jungle. Would baking soda even work? if so, it'd be cheaper for me.

I use crushed coral to bring up my pH as its 6.4 out of my tap. You can find it in the marine section of your LFS. I put it in a media bag and rinse it VERY well. Then I plop it into my media basket in my filter. My pH now stays at a steady 7.0. A big bag is only around $11 and you dont have to replace it very often.

I actually use the crushed coral in my filter's too.I use to use the baking soda,but with the amount of water changes I do,it became a pain.